Pneumatic flue-cutter.



No. 747,565. .l PATENTED DEG. 22, 1903i:

` J. T. MOGRATH. PNEUMATIG FLUE GUTTER.

APPLIOATION-IILED SEPT'. 5, 1902.

no no nnL.

UNITED STATES Patented December 22,' 1903.

PATENT OFFICE.

PNEUMATIC FLUE-CUTTER.

SPECIFICATION forming part of Letters Patent No. 747,565, dated December22, 1903. Application filed September 5, 1902. Serial No. 122,235. (Nomodel.)

To all whom it may concern:

Beit known that LJoHN THOMAS MCGRATH, master mechanic, of the town ofFort Gratiot, in the county of St. Clair, in the State of Michigan, haveinvented certain new and usefullmprovementsin Pneumatic Flue-Outters,

of which the following is a specification.

My invention relates to improvements in Hue-cutters; and the object ofthe invention is to provide a simple, cheap, positive, independentdriving means for the flue-cutter and for throwing the cutting wheeloutwardly against the interior periphery of the flue-and designed to 4beoperated pneumatically and, further, to provide a means for cleaning theinner surface of the llue before the cuttingV operation takes place; andit consists, essentially, of the novel arrangement and construction ofparts, as hereinafter more particularly explained.

Figure l-is a perspective view of my fluecutter, showing it for the mostpart in section. Fig. 2 is a detai/lof the operating-piston and rod.Fig. 3 is a cross-section on line a: w of Fig. l. Fig. 4 is a similarview on line a b of Fig. l. Fig.' 5 is a detail of the scraper, showingits detachable connection to the end of the flue-cutter. Fig. 6 is adetail of the -sleeve forming the connection between the hollowdriving-shaft and the branch air-inlet p1pe.

In the drawings like letters of reference indicate corresponding partsin each figure.

A is the casing of the line-cutter, having a peripheral recess a.

B is a central rod mental extension Z7. l

C is a bar pivotally secured to thewall of provided withthesegthe casingwithin the recess a. Vc is the cut. ting-wheel, journaled at theopposite end of the bar C. v

b' represents spiral grooves formed in the central spindle D is anair-cylindersecured to or forming part of the casing of the flue-cutter.

E is the hollow driving-shaft, operated by a suitable motor and designedto enter the head d of the cylinder D.

d' is a branch pipe connected to the hollow shaft by a sleeve d2 andprovided with a turncock cl3. (See Fig. l.) Y

In the hollow shaft E are formed openings e beneath the sleeve d2. Thesleeve d2 is heldin place by the lock-nuts d4. This connection willenable the air to be fed into the drivingshaft E at any point in itsrotation.

F is a piston designed to operate yWithin the cylinder D and providedwith a stemf, having an enlarged rectangular outer end f.

f2 is a recess into which the central rod B is designed to fit.

f4 represents ball-bearings.

f3 represents tap-screws having semicircular end recesses into which andthe spiral grooves b the balls are designed to fit and have movementtherein.

G is a compression-spring located -between the piston F and the wall ofthe cylinder to carry the said piston back to its normal posif tion whenthe cutter has finished operating on the flue.

- H is a reduced portion of the cylinder made rectangular to form aguideway forthe enlarged portion f and prevent the rotation of thepiston F.

H is a cutting-knife or scraper attached to or forming part of thecasing A and designed to clean the inner periphery of the ilue beforethe cutting-Wheel c is brought into operation, thereby preventing itbecoming clogged or rendered inoperative. V

Having described the principal parts involved in my invention, I shallbriefly describe the operation of the'same. The shaft isrstcausedtorotate by any suitable motor, and the device is moved forward, so asto bring the knife H' Within the flue, and thereby in its rotationremove any accumulation of scale or rust or foreign matter from theinterior of the due previous'to the cutter being brought into position.The device being brought still farther forward, the turncock d3 thenbeing opened air passes into the cylinder D, thus forcing the .pistonforward. By means of balls f4 operating in the grooves b a rotarymovement is imparted to the spindle B. As the segmental end b of thespindle B rotates within thev casing A it carries the wheel c outwardlyinto an operative position against the wall of the ilue to cut it. Whenthis operation is complete, the turncock d3 is closed, thereby cuttingoff the airsupply to the cylinder D. The spring G then operates to carrythe piston F back to its normal position, and thereby a rotary movementis imparted in a reverse direction to the spindle B through the balls f4and spiral ways b', allowing the cutting-wheel c to recede, and thuspermit of the withdrawal of the tool.

It will be seen from this description that the cutting-wheel will bepositively forced against the interior of the flue, so as to act withthe greatest efticiency on account of the bearings holding in theirposition in the spiral grooves, and thereby holding the segmental end ofthe spindle against the bar, so as to keep a constant pressure on thebar, and consequently on the cutter when in use.

What I claim as my invention is 1. In a flue-cutter, the combinationwith the casing having a radially-movable cutter, of a spindle rotatablymounted in the casing, adapted when rotated to force said cutteroutwardly, a reciprocating piston within the casing, and means wherebythe reciprocation of the piston imparts rotary movement to said spindle,substantially as described.

2. In a iue-cutter,the combination with the casing, the central spindleextending therethrough and the cutting-wheel adjusted and supportedthereby, of a cylinder forming part of the said casing and provided withan inletpipe, a piston designed to operate therein and suitableconnections between the piston and the central spindle for imparting aturning movement to the spindle during its rotation as and for thepurpose specified.

3. In a iiuecutter,the combination with the rotatable casing, thecentral spindle extending therethrough and having spiral grooves formedtherein and the cutting-wheel adjusted and supported by the spindle, ofa cylinder forming part of the said casing and provided with aninlet-pipe, a piston designed to operate therein, and provided with acentral hollow stem into which the central spindle is designed toextend, projecting portions formed in the interior of the stem anddesigned to enter the spiral groove to impart a turning movement to thespindle and means for returning the piston toits normal position whennot in operation as and for the purpose specified.

4. In a ue-cu tter, the combination with the rotatable casing, thecentral spindle extending therethrough and having spiral grooves formedtherein and the cutting-wheel adj usted and supported by the spindle, ofa cylinder forming part of the said casing and provided with aninlet-pipe, a piston designed to operate therein and provided with acentral hollow stem into which the central spindle is designed toextend, ball-bearings held within the spiral grooves by suitable cupsand a resilient means for restoring the piston to normal locationbetween the piston and the end of the casing as and for the purposespecified.

5. In a {lue-cutter of the class described, the

combination with the rotatable casing, the central spindle extendingtherethrough and having spiral grooves formed therein and acutting-wheel adjusted and supported by the spindle, of a cylinderattached to or forming part of the casing and having an air-inlet pipeand an outer rectangular recess, a piston located within the cylinderand provided with a stem having a rectangular end having a centralorifice designed to receive the spiralgrooved end of the spindle, ballslocated in the spiral grooves and set-screws designed to extend throughthe square portion of the stem and having cup-shape inner ends designedto receive and hold the balls in position as and for the purposespecied.

6. In a flue-cutter, the combination with the rotatable casing, thecentral spindle extending therethrough and having spiral grooves formedtherein and a cutting-wheel adjusted and supported by the spindle, of acylinder attached to or forming part of the casing and having anair-inlet pipe and an outer rectangular recess, a piston located withinthe cylinder and provided with a stem having a rectangular end having acentral orifice designed to receive the spiral-grooved end of thespindle, balls located in the spiral grooves and set-screws designed toextend through the square portion ot'l the stem and having cupshapeinner ends designed to receive and hold the balls in position and aspring located between the piston and the end of the cylinder as and forthe purpose specified.

7. In a flue-cutter, the combination with the rotatable casing, thecentral spindle extending therethrough and having spiral grooves formedtherein, and a cutting-wheel adjusted and supported on the end of thespindle, of a cylinder, a piston located within the cylinder andoperatively connected to the central spindle, and pneumatic means foroperating the piston as and for the purpose specified.

8. In a flue-cutter, the combination with the rotatable casing, thecentral spindle extending therethrough and having spiral grooves formedtherein, and a cutting-wheel adjusted and supported on the end of thespindle, of a cylinder, a piston located within the cylinder andoperatively connected to the central spindle, a hollow driving-shaftextending into the end of the cylinder and having orifices intermediateof its length, a stationary sleeve through which such shaft extends andin which such shaft is designed to rotate, such sleeve being providedwith an air-inlet pipe and being designed to cover the openings in theshaft as and for the purpose specied.

9. In a Hue-cutter, the combination with the casing provided with anopening in its periphery and the central spindle extending through thecenter of the casing and having spiral grooves at the inner end, and asegmental outer end, and a bar pivotally connected to the casing in theopening of the casing opposite the segmental end of the spindle, and thecutting-wheel journaled in the end IOO IIO

of the bar, of turning means extending into the spiral grooves andpneumatic means for operating such turning means as and for the purposespecified.

l0. In a flue-cutter, the combination with the casing provided with anopening in its periphery and the central spindle extending through thecenter of the casing and having spiral grooves at the inner end, and asegmental outer end, and a bar pivotally connected to the casing in theopening of the casing opposite the segmental end of the spindle, and thecutting-wheel journaled in the end of the bar, of a piston provided withturning means extending into the groove and pneumatic means foroperating the piston and means for restoring it to its normal positionas and for the purpose specified.

ll. In a fiue-cutter, the combination with the spindle and a cutteradjusted and supported thereon, of a scraper secured at the outer end ofthe spindle in advance of the cutter as and for the purpose specified.

l2. In a device of the class described, a scraper adj ustably held inadvance end of the cutter as and for the purpose speciied.

13. In a device of the class described, the combination with the casingin advance of the cutter, of a scraper adjustably held upon the outerend of the casing as and for the purpose specified.

14:. In a-device of the class described, the combination with the cutterhaving a threaded orifice in the end thereof, of a scraper having aWorking iattened outer end and a threaded stem designed to t into thethreaded orifice in the end of the cutter as and for the purposespecified.

JOHN THOMAS MCGRATH Witnesses: Y

THos. J. TAYLOR, D. W. NoRvvooD.

